The invention relates to a single hand timepiece having a clockwork and a single hand. In contrast to conventional timepieces that display the time of day with an hour hand and a minute hand, single hand timepieces use only a single hand for this purpose. Whereas originally the motivation to use a single hand may have been the possible simplification of a mechanical clockwork, in the present day an advantage of timepieces with only a single hand can be found especially in the particular design of the timepiece. Thus, the use of a single hand allows space for a design reduced to the essentials.
Known single hand timepieces generally have a single hand, the movement of which corresponds to a conventional hour hand. Different auxiliary means have been proposed in order to allow the most accurate possible reading of the time of day.
For example, the document U.S. Pat. No. 5,280,461 A shows a timepiece with an hour hand in which a slide is mounted that is movable in the longitudinal direction of the hour hand. Minute information should be readable from the position of the slide.
From the document U.S. Pat. No. 5,134,596 A, a single hand timepiece is known the face of which has two scales. Hour information can be read at an inner scale, and minute information can be read at an outer scale. Here, the outer scale has a graduation into five minute intervals.
From the document FR 1 422 624 A, a single hand timepiece is known whose face, in addition to an hour scale, has step-shaped lines which allow reading of minute information in 15 minute intervals.
From the document GB 185 321 A, a single hand timepiece is known the face of which has particularly fine scale graduations in minute steps. A special balancing mechanism should additionally guarantee the correct position of the tip of the hand.
Other known single hand timepieces have a single hand which rotates once in 24 hours so that day and night can be differentiated. The slower movement of the hand, compared to hand rotating in 12 hours, also makes exact reading more difficult.
Timepieces that have clockworks working separately from each other are also known, wherein one of the clockworks drives an hour hand and one a second clockwork drives a minute hand. Such timepieces are known for example from the documents DE 299 126 24 U1 and DE 20 2008 010 962 U1.
A wristwatch with a minute hand is known from the document DE 40 03 655 C1. An image disk rotates below the minute hand, wherein the appearance of the minute hand is influenced by the position of the image disk. This should allow reading of hour information at the minute hand.
A timepiece with a minute hand and an hour hand is known from the document US 2011/0299365 A1. The two hands display the time of day in the conventional manner. By pressing a button, the minute hand can be brought into a different position in which it displays the day of the current date on a special scale from 1 to 31.